Foundations Of Cognitive Science

Piaget's Stages

Piaget was among other things, a psychologist who was interested in cognitive development. After observation of many children, he posited that children progress through 4 stages and that they all do so in the same order. These four stages are described below.

The Sensorimotor Period (birth to 2 years)
During this time, Piaget said that a child's cognitive system is limited to motor reflexes at birth, but the child builds on these reflexes to develop more sophisicated procedures. They learn to generalize their activities to a wider range of situations and coordinate them into increasingly lengthy chains of behaviour.
PreOperational Thought (2 to 6/7 years)
At this age, according to Piaget, children acquire representational skills in the areas mental imagery, and especially language. They are very self-oriented, and have an egocentric view; that is, preoperational chldren can use these representational skills only to view the world from their own perspective.
Concrete Operations (6/7 to 11/12 years)
As opposed to Preoperational children, children in the concrete operations stage are able to take another's point of view and take into account more than one perspective simultaneously. They can also represent transformations as well as static situations. Although they can understand concrete problems, Piaget would argue that they cannot yet perform on abstract problems, and that they do not consider all of the logically possible outcomes.
Formal Operations (11/12 to adult)
Children who attain the formal operation stage are capable of thinking logically and abstractly. They can also reason theoretically. Piaget considered this the ultimate stage of development, and stated that although the children would still have to revise their knowledge base, their way of thinking was as powerful as it would get.

It is now thought that not every child reaches the formal operation stage. Developmental psychologists also debate whether children do go through the stages in the way that Piaget postulated. Whether Piaget was correct or not, however, it is safe to say that this theory of cognitive development has had a tremendous influence on all modern developmental psychologists.


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